如何快速圆形移动图像

Question

任何人都可以向我解释如何创建圆形路径并在其周围移动图像。

我需要的：

let circlePath = UIBezierPath(arcCenter: CGPoint(x: 100,y: 100), radius:  CGFloat(20), startAngle: CGFloat(0), endAngle:CGFloat(M_PI * 2), clockwise: true)

我发现了圆的路径是如何做的，但其余的我不知道该怎么做。我是 iOS 开发的新手。

而且，我需要在打开页面时开始此操作。

Answer 1

检查此代码，objectToMove 是来自 storyBoard 的 UIView 进行测试，这里我使用的是您的路径代码，但我添加了更多半径

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var objectToMove: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)

        let orbit = CAKeyframeAnimation(keyPath: "position")
        var affineTransform = CGAffineTransformMakeRotation(0.0)
        affineTransform = CGAffineTransformRotate(affineTransform, CGFloat(M_PI))
        let circlePath = UIBezierPath(arcCenter: CGPoint(x: 100 - (100/2),y: 100 - (100/2)), radius:  CGFloat(100), startAngle: CGFloat(0), endAngle:CGFloat(M_PI * 2), clockwise: true)
        orbit.path = circlePath.CGPath
        orbit.duration = 4
        orbit.additive = true
        orbit.repeatCount = 100
        orbit.calculationMode = kCAAnimationPaced
        orbit.rotationMode = kCAAnimationRotateAuto

        objectToMove.layer .addAnimation(orbit, forKey: "orbit")
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

我希望这对你有帮助，问候